It’s too bad that I failed in the math exam. If only I ______ hard at it!
The key _____ four modernizations lies _____ the science and education.
What one thinks and feels is mainly _____ traditions, habits and education.
Get in touch with them, for they will be anxious _____ news of your arrival.
I like the climate here _____ the wind blows .
They paid their taxes ____ cash.